| 摘要 |
A hydraulic impulse screwdriver includes a control circuit, a drive shaft, a compressed-air motor having a motor shaft, a compressed air inlet, and an outlet, a striker having a pressurizing cylinder chamber, the striker connected to the outlet of the compressed-air motor for impulse-like driving of the drive shaft, a shut-off device for torque-dependent interruption of the compressed-air inlet to the compressed-air motor, the shutoff device including a servoelement seated in the motor shaft of the compressed-air motor and forming a pressure-carrying link between the pressurizing cylinder chamber of the striker and the shut-off device, by which a torque-related signal is fed to the control circuit, which control circuit interrupts the compressed-air inlet to the compressed-air motor when a specified torque limit value is reached, a bending bar in the shut-off device that is arranged in cooperation with the servoelement, the bending bar being provided with a transducer to determine a bending moment dependent on an impulse pressure in the striker pressurizing cylinder chamber, and an electronic evaluation unit for comparing the bending moment with the specified torque limit value so that the shut-off device is operated when the specified torque limit value is reached.
|
